1. Field of the Invention
The present invention relates to a grooved profile for a form fitting hub-shaft connection with essentially trapezoid cross-section of the toothing profiles both of the hub and the shaft, such that the wall thickness at least in the region of the toothing profiles is smaller than the difference between the tip diameter and the base diameter of the toothing profile. Additionally, the present invention relates to a telescopic pipe for articulated shafts with an inner pipe and an outer pipe, such that the inner pipe or the outer pipe have the above-noted grooved profile. Further, the present invention relates to a process for the manufacture of the above-noted grooved profile.
2. Description of Background Information
Fitting keys or slide keys are often used for the form fitting connection between a hub and a shaft. When large amounts of torque are to be transferred and an axial movement between hub and shaft is to be guaranteed, as for example in articulated shafts, a multi-groove profile or a multi-wedge shaft is often used.
The grooves thereby often have either a rectangular or trapezoid profile. The profiles are produced either by machining or cold forming, for example by impact rolling processes. Compared to the machining, cold forming has the advantage to be more economical for the production in high quantities.
Such grooved profiles are used, for example, for clutch disc carriers for automatic vehicle transmissions or for articulated shaft telescopic pipes, which are used in large numbers, for example, in motor vehicle production. An inner and outer pipe with corresponding grooved profiling on the outside or inside is thereby respectfully used. Because of the large quantities required, the cold-forming process is of large interest for economical production, but the high rotation speed and load on articulated shaft telescopic pipes during operation requires a high accuracy of the profile connection between the inner and outer pipe.
Not only must the largest possible area connection between the two profiles of the pipes be created for the transfer of large amounts of torque, but a very good centering of the two pipes must also be guaranteed for the achievement of high rotation speeds.